Running Really Rich

[z_boi]

Ok, so i jus got my car running again. its runnin really rich, Theres smoke and the car is runnign rough.

I notic when i unplug the fuel pump when the car is running, that it begins to smooth out the idle or when i rev it. SO i kept tappin the fuel pump so it didnt stay on constantly and it ran jus fine. wat is rong? Fuel pressure regulator? Mafs? wat could it be? It all started after i changed the injector plugs.

[RB30-ZED]

Firstly your car maybe running rich because it thinks its cold, check the coolant temp sensor for a bad connection and operation.

Secondly if your car has a vane type air flow meter take the inlet hose off and check that the flap opens and closes with out sticking, as a back fire can bend the air door and they will stick in an open position which will give more fuel.

And last but not least get hold of a fuel pressure gauge and check the pressure by teeing in to the fuel line from the pump and the fuel rail , should be about 30psi running with the vacuum hose connected to the regulator and about 35psi with it off.

Steven

[z_boi]

i dont have a cold start injector or an air regulator. Its running really rich, even when im on the gas it sounds like its missfiring. But like i said in the other post about wat i did with the fuel pump. and when i rev'd it, it was fine. I'll try it out and see wat happens. My MAfs looks fine. i didnt have a filter on there and it opens jus fine.

[TomoHawk]

take the AFM inlet hose off and check that the flap opens and closes with out sticking, as a back fire can bend the air door and they will stick in an open position which will give more fuel.

And last but not least get hold of a fuel pressure gauge and check the pressure by teeing in to the fuel line from the pump and the fuel rail, should be about 30psi running with the vacuum hose connected to the regulator and about 35psi with it off.

Which inlet hose is that, the one between the AFM and the intake manifold? I had the side cover of the AFM off, and it looks like the flapper closes all the way.

Are you referring to the Thermotime switch, instead of the coolant sensor? I tried checking my cold-start injector according to the Haynes book, and it doesn't spray any fuel AT ALL, but the engine is still rich, and starts easily when cold.

On my engine, the vacuum line to the pressure regulator (small can on the fuel rail?) doesn't have a really good seal. Problem?

You didn't mention about adjusting the tension on the AFM flapper spring to lean out the mix.

Also, I noticed that you don't get much power off the line on mine until you push the gas pedal halfway down. I assumed that's because of the TPS switches? If so, I don't seem to notice any extra power at WOT on the highway then.

thx

[RB30-ZED]

Which inlet hose is that, the one between the AFM and the intake manifold? I had the side cover of the AFM off, and it looks like the flapper closes all the way.

Are you referring to the Thermotime switch, instead of the coolant sensor? I tried checking my cold-start injector according to the Haynes book, and it doesn't spray any fuel AT ALL, but the engine is still rich, and starts easily when cold.

On my engine, the vacuum line to the pressure regulator (small can on the fuel rail?) doesn't have a really good seal. Problem?

You didn't mention about adjusting the tension on the AFM flapper spring to lean out the mix.

Also, I noticed that you don't get much power off the line on mine until you push the gas pedal halfway down. I assumed that's because of the TPS switches? If so, I don't seem to notice any extra power at WOT on the highway then.

thx

No the hose from the air cleaner to the AFM. It should close all the way, but you should swing it open fully by pushing it open with your finger to make sure the air door/flap doesn't stick, as is very common for that type of load sensor.

No, the thermotime switch only has control of the cold start injector and only for a max of 3-4sec with cold coolant.

Im talking about the coolant temp sensor for the ECU, not to be confused with the sensor that runs the dash temp gauge. Its the ECU's temp sensor that has control over Air Fuel Ratio as a function of coolant temp. Its a negative temperature coefficient sensor, so if its got a bad connection or isn't plugged in to the harness, the ECU will think its cold and run very rich.

Can be, as its this vacuum signal that keeps the fuel pressure at a constant above manifold vacuum.

No I didn't as this is only fixing a symptom not a couse. The only time this modification can be of use is if the operating parameters of the engine change, eg a new cam ect.

This EFI system uses a switch type TPS, it should be set with is idle contacts closed at idle, the second switch in this unit will then open about 80% throttle to richen up the AFR from 14.7:1 to around 12.5:1.

Incorrect adjustment will course poor idle, but it sounds like the lack of power my be elsewhere.

Steven

[HKSZ]

My 2c

Have you got the right numbered connector to the injector, some injector leeds have the cyl # stamped faintly into them.

[z_boi]

yeah, i made sure all the injectors are in the coorect place. i looked for the number and wrote it on with whiteout so i could see it.

By adjusting the tension, wouldnt it retrict airflow tho?

[RB30-ZED]

The early Zeds use Japanese licensed copy of Bosch L-Jetronic, this system runs simultaneous injection, so they all inject the same amount at the same time, so mixing the injector plugs makes no difference.

If you can check the fuel pressure you will be able to eliminate faults related to fuel pressure or ECU.

Steven

[z_boi]

well, i checked the plug for the coolant temp switch and it was fine. I guess i'll have to check my fuel pressure with a guage and see if its that.